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| author | Vincenzo Frascino <vincenzo.frascino@arm.com> | 2020-12-22 23:01:45 +0300 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2020-12-22 23:55:07 +0300 |
| commit | bad1e1c663e0a72f9cf7b230a00d821678f80455 (patch) | |
| tree | cd623e54bc02bc56da1fe75bd71c3adcb7eab75e /arch/arm64/kernel/asm-offsets.c | |
| parent | 620954a67bcec6ca6b902baaaa1e3f2601b371a7 (diff) | |
| download | linux-bad1e1c663e0a72f9cf7b230a00d821678f80455.tar.xz | |
arm64: mte: switch GCR_EL1 in kernel entry and exit
When MTE is present, the GCR_EL1 register contains the tags mask that
allows to exclude tags from the random generation via the IRG instruction.
With the introduction of the new Tag-Based KASAN API that provides a
mechanism to reserve tags for special reasons, the MTE implementation has
to make sure that the GCR_EL1 setting for the kernel does not affect the
userspace processes and viceversa.
Save and restore the kernel/user mask in GCR_EL1 in kernel entry and exit.
Link: https://lkml.kernel.org/r/578b03294708cc7258fad0dc9c2a2e809e5a8214.1606161801.git.andreyknvl@google.com
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Co-developed-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Branislav Rankov <Branislav.Rankov@arm.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Kevin Brodsky <kevin.brodsky@arm.com>
Cc: Marco Elver <elver@google.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'arch/arm64/kernel/asm-offsets.c')
| -rw-r--r-- | arch/arm64/kernel/asm-offsets.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/arch/arm64/kernel/asm-offsets.c b/arch/arm64/kernel/asm-offsets.c index 5e82488f1b82..f42fd9e33981 100644 --- a/arch/arm64/kernel/asm-offsets.c +++ b/arch/arm64/kernel/asm-offsets.c @@ -47,6 +47,9 @@ int main(void) DEFINE(THREAD_KEYS_USER, offsetof(struct task_struct, thread.keys_user)); DEFINE(THREAD_KEYS_KERNEL, offsetof(struct task_struct, thread.keys_kernel)); #endif +#ifdef CONFIG_ARM64_MTE + DEFINE(THREAD_GCR_EL1_USER, offsetof(struct task_struct, thread.gcr_user_excl)); +#endif BLANK(); DEFINE(S_X0, offsetof(struct pt_regs, regs[0])); DEFINE(S_X2, offsetof(struct pt_regs, regs[2])); |